The use of a random numbers table for assigning subjects to groups eliminates which of the following?

Question

A) Selection threat
B) Intervention fidelity
C) Attrition
D) Carryover effects

Answer 1

A
Feedback:
A selection threat reflects biases stemming from preexisting differences between groups; use of random assignment via a random numbers table eliminates selection threat. Careful researchers pay attention to intervention fidelity—that is, they take steps to monitor that an intervention is faithfully delivered in accordance with its plan and that the intended treatment was actually received. Longitudinal studies are typically expensive, time-consuming, and subject to the risk of attrition (loss of participants over time), but yield valuable information about time-related phenomena. A crossover design has the advantage of ensuring the highest possible equivalence among the people exposed to different conditions. Such designs are inappropriate for certain research questions, however, because of possible carryover effects—that is, when subjects are exposed to two different treatments, they may be influenced in the second condition by their experience in the first. Random assignment does not eliminate intervention fidelity, attrition, or carryover effects.